Currently, it is known that there are constructively multiple suspended, built-in and fixed-on light sources to be conditionally divided into several groups:                reflected-surface lighting units,        gap lighting units, and        edge lighting units.        
Edge-lit units have a number of advantages (light weight, low cost, uniform illumination, substantially smaller light thickness etc.). Today, such lights have their thickness reduced down to 10 mm and less. But all those lights are furnished with remote large-size power supplies positioned separately (beyond a light) and designed so that it makes them very unhandy. Besides, it can be necessary to tackle different tasks for reducing labor output and cost ratio due to severe competition in the market.
A known LED lighting unit contains a light guide panel made of glass or optical plastic, and LEDs disposed close by an end surface (patent RU2565419, F21V 7/00, publication date: Oct. 20, 2015). The known solution is featured with its large thickness, weight and value.
Patent KR101604290, IPC F21V15/01 published on Mar. 17, 2016 and patent KR101340053, IPC F01B1/00 published on Dec. 10, 2013 are currently in use and contain the following patent-claim common features: a planar light guide, light-emitting diodes fitted on a card installed close by an end face of a light guide, a frame fabricated from tandem-connected pressed aluminum items having a transverse profile that is designed to have an open cavity for holding a planar light guide and a cavity for placing an LED circuit card.
A lighting unit made under patent KR101494640, IPC F21V 8/00 published on Feb. 23, 2015 is the closest known equivalent applicable as a prior art containing a planar light guide, light-emitting diodes fitted on a card installed close by an end face of a light guide, a frame fabricated from tandem-connected pressed aluminum items having a profile that is designed to have an open cavity for installing an LED circuit card; a connecting unit comprising an angle piece and cover that have a sliding joint with an inner frame wall surface and integrated threaded joints. Additionally, this unit is furnished with a power supply mounted beyond its housing due to the excess dimensions to cause problems for unit installation or removal, it has high material output ratio and no simple or effective non-insulated power supplies can be used.
Such prototypes additionally suffer from such effects as distortion since they are significantly affected by thermal loads, especially in the event of excess light emission power.
The technical result of the claimed solution is hardening its frame and improving the compaction at the expense of the monoblock design.